A comparison of chloride, bromide, and sucrose dilution volumes in neonatal pigs

Use of 36Cl, 82Br, and [3H]sucrose to estimate extracellular water volume was evaluated in 14 piglets (7-14 days old). 36Cl and 82Br were distributed in approximately the same volume, but a period of 5-6 hr after injection was required to reach equilibrium in the neonatal pig. Dilution volumes calculated before equilibration (2-5 hr) for 36Cl (326 +/- 11 ml/kg) and 82Br (328 +/- 13 ml/kg) were different from equilibration (6-8 hr) phase volumes (356 +/- 13 ml/kg and 355 +/- 13 ml/kg, respectively; P less than 0.001). A 3-hr sample estimated the same volume distribution calculated by extrapolation of the 6- to 8-hr period because of the relationship between the two slopes of the plasma clearance curves. After the 82Br and 36Cl had achieved equilibration, each was distributed in a volume equivalent to total body chloride space (362 +/- 29 ml/kg) measured by neutron activation; no statistical differences were found (P = 0.6). The early equilibration phase measured a 10% smaller, faster exchangeable fraction of total body Cl. Sucrose dilution volume (332 +/- 19 ml/kg) required multiple plasma samples for extrapolation and measured a dilution volume 7% smaller (P less than 0.05) than total body chloride space.     

Effect of leg exercise training on vascular volumes during 30 days of 6 degrees head-down bed rest.

Plasma and red cell volumes, body density, and water balance were measured in 19 men (32-42 yr) confined to bed rest (BR). One group (n = 5) had no exercise training (NOE), another near-maximal variable-intensity isotonic exercise for 60 min/day (ITE; n = 7), and the third near-maximal intermittent isokinetic exercise for 60 min/day (IKE; n = 7). Caloric intake was 2,678-2,840 kcal/day; mean body weight (n = 19) decreased by 0.58 +/- 0.35 (SE) kg during BR due to a negative fluid balance (diuresis) on day 1. Mean energy costs for the NOE, and IKE, and ITE regimens were 83 (3.6 +/- 0.2 ml O2.min-1.kg-1), 214 (8.9 +/- 0.5 ml.min-1.kg-1), and 446 kcal/h (18.8 +/- 1.6 ml.min-1.kg-1), respectively. Body densities within groups and mean urine volumes (1,752-1,846 ml/day) between groups were unchanged during BR. Resting changes in plasma volume (ml/kg) after BR were -1.5 +/- 2.3% (NS) in ITE, -14.7 +/- 2.8% (P less than 0.05) in NOE, and -16.8 +/- 2.9% (P less than 0.05) in IKE, and mean water balances during BR were +295, -106, and +169 ml/24 h, respectively. Changes in red cell volume followed changes in plasma volume. The significant chronic decreases in plasma volume in the IKE and NOE groups and its maintenance in the ITE group could not be accounted for by water balance or by responses of the plasma osmotic, protein, vasopressin, or aldosterone concentrations or plasma renin activity. There was close coupling between resting plasma volume and plasma protein and osmotic content.(ABSTRACT TRUNCATED AT 250 WORDS)     

Blood volume in inbred strain BALB/c, CBA/J and C57BL/10 mice determined by means of 59Fe-labelled red cells and 59Fe bound to transferrin.

Circulating red blood cell (RBC) and plasma volume was determined in male inbred strain BALB/c, CBA/J and C57BL/10 mice by parallel use of the 59Fe-labelled RBC dilution and the dilution of 59Fe bound to transferrin. The whole blood volumes values derived from the venous haematocrit and plasma volume were about double the values calculated from the venous haematocrit and circulating RBC volume. Comparison of the two methods thus explains the marked differences in different studies of blood volume in mice and shows that correct values can be obtained only by parallel measurements of RBC and plasma volume by separate methods, or by correcting the venous haematocrit to whole body haematocrit. Combination of the labelled RBC method and the 59Fe-transferrin method showed the blood volume values in the above strains of mice to be 10.35 +/- 0.16, 7.32 +/- 0.10 and 7.94 +/- 0.15 ml/g b.w. respectively. The ratio of whole body to venous haematocrit in these strains was was 57.3 +/- 1.6%, 68.0 +/- 1.8% and 69.5 +/- 2.2%. Significant interstrain differences were demonstrated in RBC, plasma and blood volume and in the venous and whole body haematocrit and their ratio.     

Opioid action on luteinizing hormone secretion in newborn pigs: paradoxical effect of naloxone

German Landrace piglets, 6-7 days of age, received either saline (9 males, 8 females), 0.5 mg naloxone/kg body weight (7 males, 7 females), 2.0 mg naloxone/kg (7 males, 8 females) or 0.5 mg DADLE (potent leu-enkephalin analog)/kg (7 males, 7 females) through a catheter inserted into the jugular vein 2-4 days previously. Male or female piglets were allocated randomly, within litter, to the different experimental groups. Blood samples were withdrawn for a period of 240 min at 10-min intervals for the first 60 min following injection and at 20-min intervals for the rest of the test period. Piglets were separated from their mother via a detachable wall and were allowed to suckle every 50 min. DADLE failed to alter plasma levels of LH in both males and females. Naloxone induced a significant (P less than 0.01) decrease in LH concentrations in females 10 to 60 min after injection (saline: 2.3 +/- 0.2 ng/ml plasma (SEM); 0.5 mg naloxone/kg: 1.0 +/- 0.2 ng/ml plasma and 2 mg naloxone/kg 1.2 +/- 0.4 ng/ml plasma). In males low doses of naloxone reduced plasma LH levels 10 to 40 min after injection (saline: 2.0 +/- 0.3 ng/ml plasma and 0.5 ng naloxone/kg: 1.1 +/- 0.3 ng/ml), whereas a decrease in plasma LH levels occurred 80 to 140 min after injection of high doses of naloxone (saline: 2.1 +/- 0.2 ng/ml and 2 mg naloxone/kg: 1.0 +/- 0.2 ng/ml).(ABSTRACT TRUNCATED AT 250 WORDS)     

Sensitive and simple method for the determination of nicotine and cotinine in human urine, plasma and saliva by gas chromatography-mass spectrometry

A method is proposed for the determination of nicotine and cotinine in human urine, plasma and saliva. Nicotine and cotinine were extracted from alkalinized sample with ethyl ether and concentrated to minimum volume with nitrogen stream. The volatility of nicotine was prevented by the addition of acetic acid to the organic solvent during evaporation. Peak shapes and quantitation of nicotine and cotinine are excellent, with linear calibration curves over a wide range of 1-10,000 ng/ml. The detection limits of nicotine and cotinine are 0.2 ng/ml in urine and 1.0 ng/ml in plasma and saliva. The intra-day precision of nicotine and cotinine in all samples was <5% relative standard deviation (RSD). Urine, plasma and saliva samples of 303 non-smoking and 41 smoking volunteers from a girl's high school in Korea were quantified by the described procedure. As a result, the concentrations of nicotine and cotinine in plasma ranged from 6 to 498 ng/ml and 4 to 96 ng/ml. Otherwise, those of nicotine and cotinine in saliva ranged from 0 to 207 ng/ml and 0 to 42 ng/ml, and those of nicotine and cotinine in urine ranged from 0 to 1,590 ng/ml and 0 to 2,986 ng/ml, respectively. We found that the concentration of cotinine in plasma was successfully predicted from the salivary cotinine concentration by the equation y=2.31x+4.76 (x=the concentration of cotinine in saliva, y=the concentration of cotinine in plasma). The results show that through the accurate determination of cotinine in saliva, the risk of ETS-exposed human can be predicted.     

Volume expansion during NOS substrate donation with L-arginine: regulatory offsetting of renal response?

The responses to infusion of nitric oxide synthase substrate (L-arginine 3 mg.kg(-1).min(-1)) and to slow volume expansion (saline 35 ml/kg for 90 min) alone and in combination were investigated in separate experiments. L-Arginine left blood pressure and plasma ANG II unaffected but decreased heart rate (6 +/- 2 beats/min) and urine osmolality, increased glomerular filtration rate (GFR) transiently, and caused sustained increases in sodium excretion (fourfold) and urine flow (0.2 +/- 0.0 to 0.7 +/- 0.1 ml/min). Volume expansion increased arterial blood pressure (102 +/- 3 to 114 +/- 3 mmHg), elevated GFR persistently by 24%, and enhanced sodium excretion to a peak of 251 +/- 31 micromol/min, together with marked increases in urine flow, osmolar and free water clearances, whereas plasma ANG II decreased (8.1 +/- 1.7 to 1.6 +/- 0.3 pg/ml). Combined volume expansion and L-arginine infusion tended to increase arterial blood pressure and increased GFR by 31%, whereas peak sodium excretion was enhanced to 335 +/- 23 micromol/min at plasma ANG II levels of 3.0 +/- 1.1 pg/ml; urine flow and osmolar clearance were increased at constant free water clearance. In conclusion, L-arginine 1) increases sodium excretion, 2) decreases basal urine osmolality, 3) exaggerates the natriuretic response to volume expansion by an average of 50% without persistent changes in GFR, and 4) abolishes the increase in free water clearance normally occurring during volume expansion. Thus L-arginine is a natriuretic substance compatible with a role of nitric oxide in sodium homeostasis, possibly by offsetting/shifting the renal response to sodium excess.     

The value of urine osmolality as an index of stress in the ovine fetus

In ovine fetuses, during 100-130 days of gestation, urine osmolalities less than 175 mosmol/kg water were associated with plasma immunoreactive adrenocorticotrophin (ACTH) concentrations below 40 pg/ml in 40/41 samples. In 18/29 fetuses with urine osmolalities greater than 175 mosmol/kg water plasma ACTH was significantly elevated. In 38 samples of fetal blood there was a significant correlation between plasma ADH and ACTH concentrations. By least squares regression the equation to the line was [ACTH] = 5.06 + 3.70 [ADH] (r = 0.62, P less than 0.001). In 50 samples from fetuses of gestational ages 100-140 days, with urine osmolalities of 302 +/- 86 mosmol/kg (mean +/- SD) the blood pH, pO2 and pCO2 values were not significantly different from those in 50 samples from fetuses with urine osmolalities of 125 +/- 22 mosmol/kg. It is proposed that the measurement of fetal urine osmolality provides a good index of fetal stress. A fetus with a urine osmolality less than 175 mosmol/kg is almost invariably in the optimum, unstressed condition.     

Maternal dehydration: impact on ovine amniotic fluid volume and composition

Maternal dehydration consistent with mild water deprivation or moderate exercise results in maternal and fetal plasma hyperosmolality and increased plasma arginine vasopressin (AVP). Previous studies have demonstrated a reduction in fetal urine and lung fluid production in response to maternal dehydration or exogenous fetal AVP. As fetal urine and perhaps lung liquid combine to produce amniotic fluid, maternal dehydration may affect the amniotic fluid volume and/or composition. In the present study, six chronically-prepared pregnant ewes with singleton fetuses (128 +/- 1 day) were water deprived for 54 h to determine the effect on amniotic fluid. Maternal plasma osmolality (306.5 +/- 0.9 to 315.6 +/- 1.9 mOsm/kg) and AVP (1.9 +/- 0.2 to 22.2 +/- 3.2 pg/ml) significantly increased during dehydration. Similarly, fetal plasma osmolality (300.0 +/- 0.9 to 312.7 +/- 1.7 mOsm/kg) and AVP (1.4 +/- 0.1 to 10.4 +/- 2.4 pg/ml) increased in parallel to maternal values. Amniotic fluid osmolality (276.8 +/- 5.7 to 311.6 +/- 6.5 mOsm/kg) and sodium (139.8 +/- 4.8 to 154.0 +/- 5.4 mEq/l) and potassium (9.1 +/- 1.3 to 13.9 +/- 2.4 mEq/l) concentrations increased while a significant (35%) reduction in amniotic fluid volume occurred (871 +/- 106 to 520 +/- 107 ml). These results indicate that maternal dehydration may have marked effects on maternal-fetal-amniotic fluid dynamics, possibly contributing to the development of oligohydramnios.     

Effects of atrial appendectomy on circulating atrial natriuretic factor during volume expansion in the rat

This study examined the changes in the circulating level of endogenous atrial natriuretic factor during diuresis and natriuresis produced by acute volume expansion in anesthetized rats with either bilateral atrial appendectomy (n = 9) or sham operation (n = 9). Following control measurements in the sham-operated rats, 1% body weight volume expansion with isotonic saline produced an increment in urinary sodium excretion of over 4 mueq/min (P less than 0.05) while urine volume increased by more than 20 microliter/min (P less than 0.05). These responses were associated with a significant increase in immunoreactive plasma atrial natriuretic factor from a baseline value of 82 +/- 10 pg/ml to a level of 120 +/- 14 pg/ml (P less than 0.05). In contrast, in the group of rats with bilateral atrial appendectomy an identical degree of volume expansion increased urinary sodium excretion and urine volume by only 0.61 mueq/min (P less than 0.05) and 3.07 microliter/min (P less than 0.05), respectively. In this group, immunoreactive plasma atrial natriuretic factor remained statistically unchanged from a control value of 70 +/- 12 pg/ml to a level of 82 +/- 16 pg/ml (P greater than 0.05). Comparison of the two groups indicates that the natriuresis, diuresis, and plasma atrial natriuretic factor levels during volume expansion were significantly reduced in the rats with bilateral atrial appendectomy. No differences in mean arterial pressure and heart rate were observed between the two groups. These data demonstrate that removal of both atrial appendages in the rat attenuated the release of atrial natriuretic factor during volume expansion; and this effect, in turn, was associated with a reduction in the natriuretic and diuretic responses.     

Age-related characteristics of ceftazidime pharmacokinetics in children]

To reveal possible age-dependent variations in the ceftazidime pharmacokinetics, the drug plasma concentrations were determined by HPLC in 10 children aged 2 to 13 years with peritonitis. The blood specimens were collected 0.25, 0.5, 1, 3, 6 and 8 hours after intravenous bolus administration of ceftazidime (Kefadym, Eli Lilly) in a single dose of 20 mg/kg. The mean values of the model-independent parameters were: total clearance (Cl), 3.3 +/- 0.8 ml/min.kg; steady-state distribution volume, 0.32 +/- 0.06 ml/kg; mean residence time, 1.7 +/- 0.4 hours. The C-coordinate of the gravity center was equal to 26 +/- 7 mg/l. A noticeable age-dependent decrease in Cl was detected by comparing the Cl estimates in our study for the children aged 7.0 +/- 3.0 years with earlier findings in children aged 12 years as well as in adults (18 and 26 years) and elderly patients (77 years): 2.5, 2.2, 2.0 and 1.1 ml/min.kg, respectively. A similar trend was observed for the ceftazidime volume of distribution (Varea). Due to the described reduction in Cl and Varea the age-induced changes in the half-life of ceftazidime were negligible. The age-dependent differences in ceftazidime pharmacokinetics should be taken into account in designing rational dosage regimens for the drug administration.     

Atrial natriuretic factor and renal sodium excretion during ventilation with PEEP in hypervolemic dogs.

Controlled mandatory ventilation with positive end-expiratory pressure (PEEP) reduces renal sodium excretion. To examine whether atrial natriuretic factor (ANF) is involved in the renal response to alterations in end-expiratory pressure in hypervolemic dogs, experiments were performed on anesthetized dogs with increased blood volume. Changing from PEEP to zero end-expiratory pressure (ZEEP) increased sodium excretion by 145 +/- 61 from 310 +/- 61 mumol/min and increased plasma immunoreactive (ir) ANF by 104 +/- 27 from 136 +/- 21 pg/ml. Changing from ZEEP to PEEP reduced sodium excretion by 136 +/- 36 mumol/min and reduced plasma irANF by 98 +/- 22 pg/ml. To examine a possible causal relationship, ANF (6 ng.min-1.kg body wt-1) was infused intravenously during PEEP to raise plasma irANF to the same level as during ZEEP. Sodium excretion increased by 80 +/- 36 from 290 +/- 78 mumol/min as plasma irANF increased by 96 +/- 28 from 148 +/- 28 pg/ml. We conclude that alterations in end-expiratory pressure lead to great changes in plasma irANF and sodium excretion in dogs with increased blood volume. Comparison of the effects of altering end-expiratory pressure and infusing ANF indicates that a substantial part of the changes in sodium excretion during variations in end-expiratory pressure can be attributed to changes in plasma irANF.     

Postexercise rehydration: effect of Na(+) and volume on restoration of fluid spaces and cardiovascular function.

Our purpose was to study the interaction between Na(+) content and fluid volume on rehydration (RH) and restoration of fluid spaces and cardiovascular (CV) function. Ten men completed four trials in which they exercised in a 35 degrees C environment until dehydrated by 2. 9% body mass, were rehydrated for 180 min, and exercised for an additional 20 min. Four RH regimens were tested: low volume (100% fluid replacement)-low (25 mM) Na(+) (LL), low volume-high (50 mM) Na(+) (LH), high volume (150% fluid replacement)-low Na(+) (HL), and high volume-high Na(+) (HH). Blood and urine samples were collected and body mass was measured before and after exercise and every hour during RH. Before and after the dehydration exercise and during the 20 min of exercise after RH, cardiac output was measured. Fluid compartment (intracellular and extracellular) restoration and percent change in plasma volume were calculated using the Cl(-) and hematocrit/Hb methods, respectively. RH was greater (P < 0.05) in HL and HH (102.0 +/- 15.2 and 103.7 +/- 14.7%, respectively) than in LL and LH (70.7 +/- 10.5 and 75.9 +/- 6.3%, respectively). Intracellular RH was greater in HL (1.12 +/- 0.4 liters) than in all other conditions (0.83 +/- 0.3, 0.69 +/- 0.2, and 0.73 +/- 0.3 liter for LL, LH, and HH, respectively), whereas extracellular RH (including plasma volume) was greater in HL and HH (1.35 +/- 0.8 and 1.63 +/- 0.4 liters, respectively) than in LL and LH (0.83 +/- 0.3 and 1.05 +/- 0.4 liters, respectively). CV function (based on stroke volume, heart rate, and cardiac output) was restored equally in all conditions. These data indicate that greater RH can be achieved through larger volumes of fluid and is not affected by Na(+) content within the range tested. Higher Na(+) content favors extracellular fluid filling, whereas intracellular fluid benefits from higher volumes of fluid with lower Na(+). Alterations in Na(+) and/or volume within the range tested do not affect the degree of restoration of CV function.     

Elimination of pyridoxylated polyhemoglobin after partial exchange transfusion in chimpanzees.

Partial exchange transfusion with 8.5% pyridoxylated polyhemoglobin solution [PolyHb-PPa] was performed in five male chimpanzees weighing 22-30 kg. Serial blood and urine samples were obtained for 3 days. Percutaneous liver biopsies were performed on the 3rd to 4th, and the 9th to 11th days after PolyHb-PPa administration. Mean exchange volume was 42.5 +/- 10.7 ml/kg BW (26.8-54.6 ml/kg), mean Hb dose 3.7 +/- 0.9 g PolyHb-PPa/kg BW (2.4-4.8 g/kg), mean exchange rate 56.7 +/- 7.1% (48.2-67.4%). All animals survived long-term. Analysis of the plasma Hb concentration-time data showed a first order decline at a plasma level of 3.7 +/- 0.9 g PolyHb-PPa/kg BW. Mean intravascular half-life was 14.6 +/- 3.2 h. Total renal elimination of PolyHb-PPa was about 7%. PolyHb-PPa was absorbed and stored by Kupffer cells and transformed into hemosiderin. Siderosis of Kupffer cells and renal tubules had largely subsided 10 days after PolyHb-PPa indicating subsequent in vivo degradation and metabolization of the polymerized Hb fractions.     

Systems for collection of urine in the captive common marmoset, Callithrix jacchus

Two systems are described for the collection of 24 h urine samples from the common marmoset (Callithrix jacchus). Using 84 adult animals, 1210 24-h samples were collected. Mean urinary excretion was 14.4 +/- 7.5 ml/24 h (n = 1210, mean +/- SD). No differences were observed between sexes (for 52 females, 24 h volume = 15.1 +/- 8.0 ml; for 32 males, 24 h volume = 12.5 +/- 6.0 ml). No significant differences were observed between pregnant and non-pregnant females with respect to 24 h urine volume, and bilateral gonadectomy did not influence subsequent urinary excretion in either sex. For 161 pairs of observations, the intake of drinking water (11.7 +/- 10.2 ml/24 h) and the volume of urine excreted (12.6 +/- 7.1 ml/24 h) showed a positive correlation (r = 0.406 d.f. 159, P less than 0.001: y = 0.558x + 4.247).     

Fluid volumes in rainbow trout, Salmo gairdneri: application of compartmental analysis

1. The measurement of fluid volumes by the indicator dilution technique and compartmental analysis was re-evaluated in free-swimming, undisturbed rainbow trout. 2. Plasma (33.5 ml/kg body wt) and blood (41.3 ml/kg body wt) volumes estimated by compartmental analysis from blood samples taken early (less than 5 min) after dye injection were 40% lower than volumes calculated by sampling late (greater than or equal to 80 min). 3. The rate of exchange of dye between plasma and interstitial fluid was high (48%/hr) compared to mammals (5%/hr) which supports the hypothesis that teleost capillaries have high protein permeability. 4. Total extracellular volume estimated using a single pool model (210.5 ml/kg body wt) of inulin kinetics was 20% higher than that calculated by a three pool model (172.8 ml/kg body wt).     

ACTH-, glucose- and lactate-content of swine plasma during insulin-induced hypoglycemia]

The present investigation was undertaken to determine the content of ACTH, glucose and lactate in plasma of 4 pigs (body weight 82--118 kg) during a circadian period and during an insulin hypoglycemia test using 1 IU/kg in 3 pigs (body weight 96--118 kg) and 4 pigs (body weight 20--30 kg). The plasma ACTH level at rest was 57 +/- 27 pg/ml (Mean +/- SE) for all samples in all animals during a circadian period. Significant diurnal changes were not observed. During insulin-induced hypoglycaemia plasma ACTH rose from a mean (+/- SE) basal level of 35 +/- 15 to a maximum of 673 +/- 100 pg/ml at 60 min in heavier pigs and in lighter pigs to 395 +/- 153 at 30 min and 403 +/- 145 pg/ml at 120 min. Initial ACTH responses were evident 30 min (heavier pigs) and between 0 and 15 min (lighter pigs) after insulin administration. Plasma glucose decreased from a mean (+/- SE) basal level of 80 +/- 10 to a minimum of 6 +/- 1 mg/100 ml at 60 min (heavier pigs) and from 88 +/- 3 to 16 +/- 4 mg/100 ml at 60 min (lighter pigs). After its minimum level the glucose concentration showed a slower increment in the heavier pigs as compared to lighter animals. Plasma lactate rose from a mean (+/- SE) basal level of 19 +/- 10 to a maximum of 76 +/- 42 mg/100 ml at 120 min (heavier pigs) and from 12 +/- 3 to 37 +/- 16 mg/100 ml at 150 min (lighter group). In accordance with the changes in the blood plasma levels of ACTH, glucose and lactate, the clinical symptoms of hypoglycaemia in heavier pigs were more intensive.     

HPLC-atmospheric pressure chemical ionization mass spectrometric method for enantioselective determination of R,S-propranolol and R,S-hyoscyamine in human plasma

A method for the simultaneous determination of R- and S-propranolol and R- and S-hyoscyamine in human plasma was developed, validated and applied to the analysis of samples from a clinical study. Sample preparation was performed by solid-phase extraction of 2 ml of human plasma using Oasis MCX cartridges and the enantioselective separations were achieved using a Chirobiotic V chiral stationary phase. The chromatography was carried out using gradient elution with a mobile phase composed of methanol:acetic acid:triethylamine which was varied from 100:0.05:0.04 to 100:0.05:0.1 (v/v/v) over 30 min and delivered at a flow rate 1 ml/min. The internal standard was R,S-propranolol-d7 and the analytes were quantified using a single quadrupole mass spectrometer employing APCI interface operated in the positive ion mode with single ion monitoring. The enantioselective separation factors, alpha, were 1.15 and 1.07 for S- and R-propranolol and R- and S-hyoscyamine, respectively. The standard curves were linear for all target compounds with coefficients of determination (r2) ranging from 0.9977 to 0.9999. The intra- and inter-day precision and accuracy were 相似文献   

Renal function and fractional clearances of American river otters (Lutra canadensis)

The finely lobulated kidneys of American river otters (Lutra canadensis) are not visualized on plain abdominal radiographs. Similar values for blood urea nitrogen (BUN), creatinine, and uric acid were obtained on different analytical systems used in 1984 and 1985. The mean +/- SD for measured plasma osmolalities (309.80 +/- 8.86 mOsmol/kg) of otters in 1985 was significantly (P less than 0.01) less than that of calculated serum osmolalities in the same 1985 specimens (321.61 +/- 5.64 mOsmol/kg) and in 1984 specimens (322.20 +/- 7.16 mOsmol/kg). Urine specific gravities and osmolalities were highly correlated (r = 0.92). On routine urinalysis, protein and bilirubin were frequent chemical findings, and urobilinogen was present in all urine samples. White and red blood cells and epithelial cells were frequent findings on urine microscopic examinations. Proteus mirabilis was cultured from four of four female otters with genitourinary infections. The mean +/- SD creatinine values for paired serum and urine samples (n = 13) were serum creatinine (Scr) 0.66 +/- 0.09 mg/dl and urine creatinine (Ucr) 186.9 +/- 55.6 mg/dl. Corresponding values for serum electrolytes (Se) and urine electrolytes (Ue) yielded mean +/- SD calculated renal fractional clearances (FC = Ue/Se x Scr/Ucr) of sodium 9.65 +/- 5.81 x 10(-4), potassium 4.15 +/- 2.01 x 10(-2), chloride 10.81 +/- 5.33 x 10(-4), calcium 4.52 +/- 4.46 x 10(-3), and phosphate 6.58 +/- 3.44 x 10(-3).     

Chlorpheniramine : I. Rapid quantitative analysis of chlorpheniramine in plasma,saliva and urine by high-performance liquid chromatography

A method was developed for the rapid quantitative analysis of chlorpheniramine in plasma, saliva and urine using high-performance liquid chromatography. A diethyl ether or hexane extract of the alkalinized biological samples was extracted with dilute acid which was chromatographed on a reversed-phase column using mixtures of acetonitrile and ammonium phosphate buffer as the mobile phase. Ultraviolet absorption at 254 nm was monitored for the detection and brompheniramine was employed as the internal standard for the quantitation. The effects of buffer, pH, and acetonitrile concentration in the mobile phase on the chromatographic separation were investigated. A mobile phase 20% acetonitrile in 0.0075 M phosphate buffer at a flow-rate of 2 ml/min was used for the assays of plasma and saliva samples. A similar mobile phase was used for urine samples. The drug and internal standard were eluted at retention volumes of less than 17 ml. The method can also be used to quantify two metabolites, didesmethyl- and desmethylchlorpheniramine, in the urine. The method can accurately measure chlorpheniramine levels down to 2 ng/ml in plasma or saliva using 1 ml of sample, and should be adequate for biopharmaceutical and pharmacokinetic studies. Various precautions for using the assay are discussed.     

A comparison of leptin and ghrelin levels in plasma and saliva of young healthy subjects

In the last 10 years, saliva has been increasingly used as a diagnostic fluid and in predictions of disease progression. Leptin and ghrelin are synthesized in several tissues including the salivary glands. The action of ghrelin is antagonistic to that of leptin. This study was undertaken to measure and compare the saliva ghrelin-leptin and plasma ghrelin-leptin levels in healthy young subjects. In 30 healthy subjects, after an overnight fast, saliva and plasma leptin levels were measured using the ELISA method while saliva and plasma immunoreactive ghrelin levels were measured using a commercial radioimmunoassay (RIA). The latter uses 125I-labeled bioactive ghrelin as a tracer and a rabbit polyclonal antibody raised against full-length octanoylated human ghrelin (Phoenix, Europe, Karlsruhe, Germany). The results of this investigation revealed that saliva leptin levels (6.19+/-2.10 microg/l) were lower than plasma levels (7.39+/-3.23 microg/l) while saliva ghrelin levels (188.5+/-84.7 pg/ml) were higher than plasma levels (126.4+/-38.5 pg/ml), when male and female subjects were considered together. Saliva leptin levels (5.93+/-1.94 microg/l) were lower than plasma levels (6.22+/-2.92 pg/ml) while saliva ghrelin levels (190.3+/-80.2 pg/ml) were higher than plasma levels (120.4+/-35.7 pg/ml) in young males. Saliva leptin levels (6.47+/-2.29 microg/l) were lower than plasma levels (8.73+/-3.14 microg/l) while saliva ghrelin levels (183.2+/-90.2 pg/ml) were higher than plasma levels (129.3+/-42.8 pg/ml) in young females, and both saliva and plasma leptin levels were slightly lower in male subjects in comparison with female subjects. Also, Immunohistochemistry study indicated that ghrelin positivity was found in ductus epithelium of salivary gland. We have demonstrated for the first time that saliva ghrelin levels were higher than in plasma while saliva leptin levels were almost the same as in plasma. Measurements of ghrelin and leptin in saliva is non-invasive, simple, and generally much preferred by patients and thus may be an acceptable alternative to plasma sampling.